Collapsible tap.



PATENTED JAN. 16, 1906.

W. A. LEONARD.

GULLAPSIBLE TAP.

APPLICATION FILED JAN. 28. 1905.

Awomsvs 5 No.1 810,289. PATENTED JAN. 16 L906. W. A. LEONARD. GOLLAPSIBLE TAP.

APPLICATION FILED JAN. 28. 1905.

2 SHEETS-SHEET 2.

21 MW :P EML ATTORNEYS UNITED STATES PATENT ()FFIG E.

WILBUR A. LEON RD. OF NEW HAVEN, CONNECTICUT, ASSIGNOR, BY

MEsNE ASSIGNMENTS, TO THE GEOMETRIC OOL COMPANY, or NEW HAVEN, CONNECTICUT, A CORPORATION OF CONNECTICUT.

' COLLAPSIBLE TAP.

Specification of Letters Patent;

Patented J an. 16, 19k 6.

To all whom it may concern.-

Be it known that LWILBUR A. LEONARD, a citizen of the United States of America, re siding in the city of New Haven, county of New Haven, State of Connecticut, have invented an Improved Collapsible Tap, of which the following is a specification.

The object of this invention is to produce a simple, easily-constructed, and readily-assembled automatic or collapsible tap, which will be thoroughly reliable in operation.

In the accompanying drawin s, Figure 1 is a plan view,-with portions bro en away, of my improved tap with the cutters set to cutting position. Fig. 2 is a similar view of part of the tool with parts shown in the collapsed positions. Fig. 3 is a side elevation, with parts broken away and parts in section, of a tap in the position of Fig. 2. Fig. 4 is a vertical longitudinal central section of a tap of slightly difierent proportions than that of the preceding figures. Fig. 5 is an end view with the cap or end plate removed. Fig. 6 is an end View. Fig. 7 is a side elevation of the plunger. Fig. 8 is an end view'of the plunger. Fig. 9 is a side View of one of the cutters, and Fig. 1.0 is an end view of the cutter.

My invention principally relates to the plunger and cutter connections. .The cut ters 1, which are referably tapering in breadth, Figs. 4 and 9, are each provided with the usual thread-cutting teeth 2 on their outer surface. On one of its side surfaces is formed an oblique groove 10, preferably par allel to the inner edge of the cutter. -These cutters fit into radial slots 3 near the end of the stock 5. The longitudinallymovable plungerfi is formed with radial webs 7, each projecting into a cutter-slot and provided with an oblique groove 8, forming a projecting rib 9, adapted to fit the groove 10 of the cutter. These oblique ribs and grooves form wedges in their action on the cutters. The spindle 1 1 of the plunger enters a central hole 12 of the stock and is movable therein by a pin 13, fast in the spindle 11 and passing .than does cam-face 18.

or inward, as the direction of the motion is forward or backward.

I provide a spring 15, secured to a threaded adjustable rod 16* and to the end of the spindle 11, to tend to withdraw the plunger, and Iprovide a rotary cam-collar 16 on the stock to project the plunger and so set the cutters to working position.

The cam-collar 16 can have'a limited rotary motion upon the stock 5, and it has on its forward edge three surfaces, against which the cross-pin 13 of the plunger-spindle may rest. One such surface 17 is a deepdepression, allowing the pin to be drawn in by the spring 15 to entirely retract the cutters, while cam-faces 18 and 19, connected on 0pposite sides of surface 17,- differ slightly from each other in height, both being adapted to project the plunger and cutters .to cut; but cam-face 19 projects them a little farther Back of the camcollar16is a ring 20, held in place by athreaded ring 21, screwed onto the stock. The collar 16 has a stud or handle 22, which is operated to throw the cross-pin 13 and its plunger onto any one of the three cam-faces 17, 18, or 19, as may be desired.

To make the withdrawal of the cutters or collapsing of the tap automatic, I make the An abutment-ring 30 of the usual type surrounds the stock and cutters and is secured to the casing 23 by means of side brackets 31, having slots 32, through which fastening-screws 33 pass to fasten them to the casing.

In operation, the cutters being in the working position shown in Fi 1, the stock 5 either rotates and enters t e material to be tapped or the stock is held stationary and the material to be threaded is rotated and one or other is fed forward. In either case the cutters enter and cut the thread to that depth determined by the height of the cam-face 18 (in the case illustrated) and to that length of threaded surface determined by the position of the abutment-collar 30. When the collar is struck by the material, the sleeve 23 is moved longitudinally backward on the stock, thereby causing the incline 24 to force the stud 22 and cam-collar 16' toward the central 'position of Figs. 2, 3, and 4 and permittlng the spring 15 to draw the spindle 11 and plunger 6 backward, with the lunger cross-pin 13 bearing against the camage 17. As the plunger 6 moves backward it will draw the cutters radially inward from the work, which may be then slip ed ofi the end of the stock or the tool with rawn from the work. 1

If a finely-finished thread is desired, I may rotate the cam-collar by means of the handlestud 22 to the opposite corner of the camopening 23* in the casing 23, adjacent to the incline 25, so as to cause the surface 19 to move the plunger 6 and spindle 11, and consequently project the cutters farther out than before, whereupon the action first described may be repeated to cut a deeper and better-finished threads Although I have described my invention as embodled in a tap, it will be understood that some of the features may be embodied in screw-cutting dies.

I claim as my invention 1. A collapsible screwthread-cutting implement, comprising a slotted stock, cutters in the slots, and a plunger longitudinally movable in the stock, with radial webs on the plunger projecting into the cutter-slots with wedge-surfaces to act on the cutters.

2. A collapsible screw-thread-cutting implement, comprising a slotted stock, cutters in the slots, a plunger longitudinally movable in the stock, wedge-surfaces between the plunger and cutters adapted to positively move the cutters upon the movement of the plunger, in combination with a pin in the pl er, a cam for said pin, an abutmentsieeve a apted for longitudinal movement plement, comprising a slotted stock, cutters in the slots, 9. plunger longitudinally movable in the stock, wedge-surfaces between the plunger and cutters ada ted to positively move the cutters upon the movement of the plun er, in combination with a crosspin on the plunger, a cam-collar rotatable on the stock avin oppositely-inclined camfaces of different Insights and means for causing either of said faces to move the plunger- 4. A collapsible screw-thread-outting implement, comprising a slotted stock, cutters 1n the slots, a plunger longitudinally movable in the stock, wedge-surfaces between the plunger and cutters. ada ted to positively move the cutters upon the movement of the plunger, in combination with a crosspin on the plun er, a cam-collar rotatable on the stock am? engaged by said cross-pin, a back-stop for the collar, an operatingstud for the earn, an abutment-sleeve longitudinally movable on the stock,-and means for preventing its rotation thereon, a camgroove in the casing through which the camstud projects and a return-spring for the plunger.

5. In combination, a stock having radial slots for the cutters and a plun er having radial webs projectin intosai radial slots to there enga e sai cutters to move them inwardly, an outwardly by longitudinal movement of the plunger.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses. j

WILBUR A. LEONARD. Witnesses:

EDITH M. BUCKBEE,

O. C. CHATFIELD. 

